Electrically powered oven, in particular for baking or heating sliced bread, and heating procedure

ABSTRACT

The electrically powered oven, in particular for baking or heating sliced bread, comprises a box-shaped body inside which there are housed one or more electrical resistors adapted to radiate energy into the body for baking or heating sliced bread. A resistor is arranged into the body, so as to determine at least two baking chambers, and exhibits baffle means adapted to direct the radiated energy towards the baking chambers. The procedure for heating the electrically powered oven in particular for baking or heating sliced bread consists in radiating energy mainly towards the lower portion of the oven by a resistor, which is arranged in an intermediate position of the box-shaped body of the oven and which determines at least two baking chambers, so that the effect of natural convection into the two baking chambers is comparable.

The present invention relates to an electrically powered oven, inparticular for baking or heating sliced bread, and to a heatingprocedure.

In particular in the following description, reference shall be made toelectrically powered ovens, that is, provided with electrical resistorscapable of radiating energy in the form of infrared radiations.

Ovens of this type comprise a box-shaped body provided with electricalheating resistors arranged at their upper and lower walls.

Ovens of this type define a single baking chamber and therefore exhibita very restricted capacity (in fact, such ovens are often small sized).

Moreover, despite the small size, the distance of upper and lowerresistors is too much to allow baking sliced bread on both faces evenly,quickly and with a low energy consumption.

Multiple baking-chamber ovens have been developed in order to increasethe oven capacity and reduce the distance of resistors from the slicedbread.

Such ovens exhibit an inside intermediate wall which usually delimitstwo baking chambers reciprocally superimposed.

Moreover, in order to ensure a good radiance, and therefore sufficientlyquick and even baking or heating, traditional ovens are provided withadditional resistors arranged at each of the two faces of theintermediate wall.

However, traditional ovens exhibit several disadvantages that occur bothduring use and during production.

In fact in the first case the advantages mainly relate to the highelectrical consumption caused by the dual central resistor and to thegreat difficulty of cleaning the baking chambers, since the resistorshoused in the proximity of the intermediate wall hinder access to thesame and make access to the farthest edges from the access port verydifficult.

Moreover, sliced bread must be arranged as close as possible to theresistors to optimise the sliced bread toasting.

This implies that in such ovens it is not possible to bake otherfoodstuff besides slices of bread.

In fact, due to the limited distance between the foodstuff to bake andthe resistors, and due to the high temperatures at which the sameresistors are brought, traditional ovens are not suitable for bakingother products than slices of bread.

In products that are not sliced bread, in fact, it is necessary tosupply thermal energy very slowly so as to optimise thermal diffusionfrom outermost to innermost layers in order to prevent burning thesurface of the foodstuff being baked before heat diffuses inside it fora complete baking of the product, due to the high resistor temperature.

On the other hand in the second case, the fact of having to apply anintermediate wall into the oven body and two electrical resistorsimplies several additional treatments and costs due to the higher numberof elements used.

Therefore, the technical task of the present invention is to realise anelectrically powered oven, in particular for baking or heating slicedbread, and a heating procedure thereof, which should allow eliminatingthe technical disadvantages of the prior art.

Within the scope of this technical purpose, an object of the inventionis to realise an oven whose electrical consumption should be lower thantraditional ovens, number of baked slices of bread being equal.

Another object of the invention is to realise an oven which should beeasy to clean in all of its parts, also at the edges that are far fromthe access port.

A further object of the invention is to realise an oven which should besuitable for baking various products, also different from slices ofbread, thoroughly and without burning their surface.

Last but not least, another object of the invention is to realise anoven with restricted costs and times compared to what required withtraditional ovens, and which should be capable of baking up to sixslices of bread at the same time (six above and six below).

The technical task, as well as these and other objects according to thepresent invention are achieved by realising an electrically poweredoven, in particular for baking or heating sliced bread, comprising abox-shaped body inside which there are housed one or more electricalresistors intended to radiate energy into said body for baking orheating said sliced bread, characterised in that at least one resistoris arranged into said body so as to determine at least two bakingchambers and exhibits baffle means intended to direct said radiatedenergy towards said baking chambers.

Advantageously, the present finding also relates to a procedure forheating an electrically powered oven, in particular for baking orheating sliced bread, characterised in that it consists in radiatingenergy mainly towards the lower portion of said oven by at least oneresistor, which is arranged in an intermediate position of thebox-shaped body and which determines at least two baking chambers, sothat the effect of natural convection into said baking chambers iscomparable.

Moreover, further features of the present invention are defined in theother claims.

Further features and advantages of the invention will appear moreclearly from the description of a preferred but non-limiting embodimentof the electrically powered oven, in particular for baking or heatingsliced bread, and of the procedure for heating it according to thefinding, where the oven is shown by way of a non-limiting example in theattached drawings. In such drawings:

FIG. 1 shows a perspective view of an oven according to the presentfinding, without a portion of its box-shaped body;

FIG. 2 shows an enlarged detail of the baking chambers of the ovenaccording to the finding; and

FIG. 3 shows an enlarged detail of a support frame and of an electricalresistor of the oven according to the finding.

With reference to the figures mentioned above, an electrically poweredoven, in particular for baking or heating sliced bread, is shown andglobally referred to with reference numeral 1.

Oven 1 comprises a box-shaped body 2 (only partly shown) inside whichthere are housed one or more electrical resistors 3 intended to radiateenergy into body 2 to bake or heat the sliced bread (not shown).

Advantageously, a resistor 4 is arranged into body 2 (in an intermediateposition between the upper and lower walls) so as to determine at leasttwo baking chambers 5, 6; advantageously, resistor 4 exhibits bafflemeans 7 adapted to direct the radiated energy towards the bakingchambers 5, 6.

The baffle means 7 comprises first elongated members 8 arranged at thesides of at least one portion (and in particular, of two portions 20) ofresistor 4; the two portions 20 of resistor 4 are reciprocally jointedby other shorter portions 21 and 22 of the same resistor 4.

In the example shown, the two reciprocally parallel portions 20 ofresistor 4 are sided at the two sides by the elongated members 8.

Such first members 8 are connected to a support frame 9 and define seatswherein portions of resistor 4 are slidably held.

In this way, frame 9 can support resistor 4, thereby overcoming allproblems related to the deformations undergone by resistor 4 and byframe 9 itself due to the high temperatures.

Advantageously, the support frame 9 allows heat transfer by convectionbetween the two baking chambers 5, 6; in fact, as shown in the attachedfigures, frame 9 exhibits a grid-like structure, but in other examplesframe 9 exhibits a plate-like structure provided with several airpassages between the two baking chambers 5, 6.

Moreover, the support frame 9 exhibits bars bent upwards 10 connected tofirst members 8 and portions 11 bent inwards, so that resistor 4 is heldbetween the seats and the bent portions 11 of frame 9.

Moreover, the baffle means 7 also comprises second members 12 adapted tohinder the radiation of radiating energy towards the upper portion ofbody 2 of oven 1.

In particular the second members 12 exhibit an elongated shape and arearranged above at least one portion of resistor 4.

In the example shown, each of the two portions at which members 8 areconnected is overlapped by an elongated member 12.

In a first embodiment of the oven according to the finding (shown in theattached figures), the first and/or second members are realised by barsconnected to the support frame 9.

In a second embodiment (not shown in the attached figures), the firstand/or second members are made of a bent sheet connected to the supportframe.

In order to improve the radiance distribution, besides members 12 thatpartly hinder the energy radiated by resistor 4 towards the upperportion of body 2 of oven 1, the two short opposed portions 21 and 22 ofresistor 4 remain cold upon switch on.

In substance, therefore, heat is only radiated by portions 20 of theresistor, thereby avoiding zones of the slices of bread from beingradiated unevenly.

This allows an even baking of the twelve slices of bread, therebypreventing some slices from being more baked than other slices of bread.

The operation of the electrically powered oven in particular for bakingor heating sliced bread according to the invention clearly appears fromwhat described and illustrated. In particular, it substantially is asfollows.

In particular, the slices of bread are arranged into the box-shaped body2 and the oven is switched on (for example, by setting a timer).

Resistors 3, 4 heat up and start radiating energy into the box-shapedbody 2, which bakes or heats the slices of bread.

Baking is effective since the intermediate resistor 4 radiates both theupper chamber 5 and the lower chamber 6 at the same time.

Moreover, the same intermediate resistor 4 preferably radiates towardsthe lower baking chamber 6; the lower baking chamber 6 therefore tendsto heat more than the upper baking chamber 5; this generates convectivemotions that allow a very even heat distribution between the two bakingchambers which, in the practice, prevent hot air from accumulating inthe upper baking chamber.

This allows considerably improving the baking evenness.

Of course, even though reference is always made to the baking or heatingof sliced bread, the oven according to the present finding can be usedfor any type of food.

In a preferred embodiment, the oven according to the finding exhibitsresistor control means adapted to repeatedly switch on and off theresistors to prevent their surface from reaching a sufficiently hightemperature, thereby generating an intense radiance.

Advantageously, the control means is adapted to detect the temperatureinto the oven and switch the resistors on or off also in relation withsuch temperature.

The control means comprises, for example, an amperometric bimetallicthermostat electrically connected in series to the resistors, adapted toget deformed (switching the resistors on or off) due to the temperatureinside the oven.

Advantageously, such thermostat is also sensitive to the currentabsorbed by the resistors.

Such current produces a further overheating of the thermostat sensitivemember which adds to that of the air heated by the resistors.

In the practice, therefore, the resistor power supply currentcontributes to heating the bimetallic thermostat with very quickresponse times and therefore, very frequent successive switching on andoff of the resistors.

In this way the maximum temperature reached by the resistor surfaceremains limited and the radiance effect is therefore reduced.

The present finding also relates to a procedure for heating anelectrically powered oven in particular for baking or heating slicedbread.

The procedure consists in radiating energy mainly towards the lowerportion of the oven by at least one resistor 4, which is arranged in anintermediate position of the box-shaped body 2 of oven 1 and whichdetermines at least two baking chambers 5, 6, so that the effect ofnatural convection into the baking chambers 5, 6 is comparable.

Advantageously, the procedure according to the present finding providesfor the repeated switching on and off of the resistors, so as to limitthe maximum temperature reached by their surface for limiting itsradiance.

In the practice, it has been proved that the electrically powered oven,in particular for baking or heating sliced bread, and the procedure forheating it according to the invention, are especially advantageous sincethey allow realising ovens which exhibit low consumption and requirelower production costs compared to traditional ovens.

The electrically powered oven, in particular for baking or heatingsliced bread, and the procedure for heating it thus designed can besubject to several changes and variants, all falling within the scope ofthe inventive idea; moreover, all details can be replaced withtechnically equivalent elements.

In the practice, the materials used as well as the sizes can be of anytype according to the requirements and to the prior art.

1. Electrically powered oven, in particular for baking or heating slicedbread, comprising a box-shaped body inside which there are housed one ormore electrical resistors intended to radiate energy into said body forbaking or heating said sliced bread, characterised in that at least oneresistor is arranged into said body so as to determine at least twobaking chambers and exhibits baffle means intended to direct saidradiated energy towards said baking chambers.
 2. Electrically poweredoven according to claim 1, characterised in that said baffle meanscomprises first elongated members arranged at the sides of at least oneportion of said resistor.
 3. Electrically powered oven according toclaim 1, characterised in that said first members are connected to asupport frame and define seats wherein portions of said resistor areslidably held.
 4. Electrically powered oven according to claim 1,characterised in that said support frame allows heat transfer byconvection between the two baking chambers.
 5. Electrically powered ovenaccording to claim 1, characterised in that said support frame exhibitsbars bent upwards connected to said first members, said frame exhibitingportions bent inwards, so that said resistor is held between said seatsand said bent portions of said frame.
 6. Electrically powered ovenaccording to claim 1, characterised in that said baffle means comprisessecond members adapted to hinder the radiance of said radiating energytowards the upper portion of said body of said oven.
 7. Electricallypowered oven according to claim 1, characterised in that said secondmembers exhibit an elongated shape and are arranged above at least oneportion of said resistor.
 8. Electrically powered oven according toclaim 1, characterised in that said first and/or said second members arerealised by bars connected to said support frame.
 9. Electricallypowered oven according to claim 1, characterised in that said firstand/or said second members are made of bent sheet connected to saidsupport frame.
 10. Electrically powered oven according to claim 1,characterised in that two shorter and opposed portions of said resistorremain cold upon switch on of said resistor.
 11. Electrically poweredoven according to claim 1, characterised in that it exhibits resistorcontrol means adapted to repeatedly switch said resistors on and off toprevent their surface from reaching a sufficiently high temperaturethereby generating an intense radiance.
 12. Electrically powered ovenaccording to claim 1, characterised in that said control means isadapted for detecting the temperature inside said oven and is adapted toswitch the resistor on an off also in relation to said temperature. 13.Electrically powered oven according to claim 1, characterised in thatsaid control means comprises an amperometric bimetallic thermostatelectrically connected in series to said resistors, said thermostatbeing adapted to switch on due to the temperature inside the oven andmoreover, due to the heat produced by the power supply current of saidresistors.
 14. Procedure for heating an electrically powered oven, inparticular for baking or heating sliced bread, characterised in that itconsists in radiating energy mainly towards the lower portion of saidoven by at least one resistor, which is arranged in an intermediateportion of the box-shaped body of the oven, and which determines atleast two baking chambers, so that the effect of natural convection intosaid chambers is comparable.
 15. Procedure according to claim 1,characterised in that it provides for the repeated switching on an offof the resistors so as to limit the maximum temperature reached by theirsurface for limiting the radiance.
 16. (canceled)